This invention relates to a memory programmable control with a central processing unit which is connected to a program memory for receiving a control program, as well as with input modules having a number of inputs for the signal states from the process and with output modules having a number of outputs for the output states for the process. Such a memory-programmable control is known from Siemens-Zeitschrift 48 (1974), Supplement "Integrated Building Block Systems SIMATIC" pages 43 to 46, as well as Siemens-Zeitschrift 51 (1977), pages 261 to 265.
In memory programmable controls known heretofore, the central processing unit cooperates directly with the peripheral equipment connected to the inputs of the input modules and the outputs of the output modules, respectively, for instance, with indicating devices and control elements. This limits the processing speed of the control. Since a control program prescribes the sequential cyclic working up of instructions, it is possible that, during a processing cycle, outputs will be addressed in a logically contradictory manner. This can lead to a brief response of the peripheral equipment connected to an output of an output module, for instance, a signal amplifier. The error possibility is detrimental particularly in the case of inductive loads.